SHIJIAZHUANG - Heavy fog blanketed north China Tuesday, grounding flights, suspending ships and causing fatal accidents.

Five car accidents occurred on a section of the Beijing-Shanghai expressway in northern Cangzhou city, Hebei province Tuesday, leaving one person dead and 10 vehicles damaged.

Thick fog and low visibility were the main causes of the accidents, said local traffic police.

The injured were rushed to hospital. Rescue efforts were concluded around 3:30 pm, said police.

Meanwhile, high-speed vessels into the eastern coastal city of Qingdao, Shandong Province, have been suspended, as smog covered the city this morning, reducing the visibility to 500 meters, according to the city's meteorological bureau.

The National Meteorological Center said fog had also covered the central and eastern parts of Henan province, northern Anhui province, central and southern Hebei province and Shandong province, as well as southwestern Yunnan province and the municipality of Tianjin this morning.

Visibility in some of these areas will decrease to less than 500 meters, the center said, noting that local meteorological centers in Tianjin, Hebei and Henan have issued warnings about the fog.

More than 100 flights were canceled or delayed in Beijing due to smog. It began to clear after the wind speed picked up around midday.

The neighboring Hebei province was also shrouded in thick smog Tuesday. The provincial weather bureau said the foggy weather hit at least eight cities including Shijiazhuang, the provincial capital. In the worst-hit areas, visibility was less than 50 meters.

In Anhui province, three people died and at least 10 others were injured in smog-related collisions and pile-ups Tuesday morning, the local fire prevention bureau said.

The center warned that people travelling in the affected regions should drive slowly for safety reasons.

The center also said Heilongjiang province and the northeast Inner Mongolia autonomous region, which experienced sharp temperature drops on Tuesday morning, will continue to see temperatures around negative 40 degrees Celsius early Wednesday.

Meanwhile, rain and snow are likely to fall in areas along the Yangtze River over the next 24 hours, with western Guizhou rrovince experiencing icy rain, the center said.

Many parts of north China, including the Xinjiang Uygur autonomous region, Inner Mongolia, Jilin province and the Qinghai-Tibet Plateau will also see snow, the center added.

China is currently on the third day of its 40-day Spring Festival travel rush. A total of 3.16 billion passenger trips are expected during the holiday.